Astrophytum myriostigma is a beautiful small cactus that has received the prestigious Award of Garden Merit of the UK's Royal Horticultural Society.
Scientific Name
Astrophytum myriostigma Lem.
Common Name(s)
Bishop's Cap, Bishop's Cap Cactus, Bishop's Hat, Bishop's Hood, Bishop's Miter Cactus
Synonym(s)
Echinocactus myriostigma, Astrophytum myriostigma subsp. myriostigma
Scientific Classification
Family: Cactaceae
Subfamily: Cactoideae
Tribe: Cacteae
Genus: Astrophytum
Etymology
The specific epithet "myriostigma (my-ree-oh-STIG-muh)" means "many-spotted" and refers to the abundance of tiny, woolly scales covering the stem of this species.
Origin
Astrophytum myriostigma is native to the highlands of northern and central Mexico. It grows in rocky, calcareous soils at elevations ranging from 2,240 to 4,920 feet (750 to 1,500 m).
Description
Astrophytum myriostigma is a spineless cactus with a bright green, typically solitary stem densely covered with tiny white woolly scales. Initially, the stem is round with five broad, prominent ribs that taper to an acute point. As the plant ages, the stem may acquire more ribs and become more columnar, reaching up to 40 inches (1 m) in height and 8 inches (20 cm) in diameter. The edges of the ribs are lined with wooly, brownish to greyish areoles.
When mature, this cactus produces fragrant, glossy yellow flowers from the areoles at the tip of the stem from spring to fall. The flowers are funnel-shaped, measuring up to 3 inches (7.5 cm) in length and 2 inches (5 cm) in diameter. They appear in succession and last for about two days. The fruits are greenish to reddish and covered with overlapping brown scales with long wool in their axil. They are oval, contain dark brown seeds, and can grow up to 1 inch (2.5 cm) in diameter.
How to Grow and Care for Astrophytum myriostigma
Light: This cactus thrives in bright, indirect light. Although it can handle some direct sun, too much of it can cause sunburn. If you are growing it indoors, it is best to place it near a window with plenty of indirect sunlight or under grow lights.
Soil: For optimal growth, Astrophytum myriostigma requires well-drained soil. Use a typical cactus potting mix, or make your own.
Temperature: This cactus prefers hot temperatures above 70 ˚F (21 ˚C) during the summer and cooler, more temperate winters. Protect it from cold drafts and frost. It grows best in USDA Plant Hardiness Zones 9b to 11b, with average minimum winter temperatures ranging from 25 to 50 °F (-3.9 to 10 °C).
Watering: Astrophytum myriostigma prefers dry conditions, with sporadic watering in the summer and a dry winter. Water the plant infrequently during spring and fall.
Fertilizing: Using a low-balanced soluble fertilizer diluted to half the recommended strength can help your cactus thrive but suspend feeding in winter.
Repotting: Regular repotting helps this cactus grow better, so repot Astrophytum myriostigma at the beginning of the growing season for the best results.
Propagation: This cactus can be propagated by seed, but its seeds are fairly fragile, so be gentle with them and soak them before sowing.
Learn more at How to Grow and Care for Astrophytum.
Toxicity of Astrophytum myriostigma
Astrophytum myriostigma has no reported toxic effects.
Varieties and Cultivars of Astrophytum myriostigma
- Astrophytum myriostigma var. nudum
- Astrophytum myriostigma var. quadricostatum
- Astrophytum myriostigma 'Onzuka'
- Astrophytum myriostigma 'Onzuka Quadricostatum'
Links
- Back to genus Astrophytum
- Succupedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus
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